Under the Waxman-Markey climate bill that may be voted on today by the U.S. House, refiners would have to buy allowances for carbon dioxide spewed from their plants and from vehicles when motorists burn their fuel. Imports would need permits only for the latter, which ConocoPhillips Chief Executive Officer Jim Mulva said would create a competitive imbalance.

“It will lead to the opportunity for foreign sources to bring in transportation fuels at a lower cost, which will have an adverse impact to our industry, potential shutdown of refineries and investment and, ultimately, employment,” Mulva said in a June 16 interview in Detroit. Houston-based ConocoPhillips has the second-largest U.S. refining capacity.

The same amount of gasoline that would have $1 in carbon costs imposed if it were domestic would have 10 cents less added if it were imported, according to energy consulting firm Wood Mackenzie in Houston. Contrary to President Barack Obama’s goal of reducing dependence on overseas energy suppliers, the bill would incent U.S. refiners to import more fuel, said Clayton Mahaffey, an analyst at RedChip Cos. in Maitland, Florida.

“They’ll be searching the globe for refined products that don’t carry the same level of carbon costs,” said Mahaffey, a former Exxon Corp. refinery manager.”